This invention relates in general to a method of forming structural elements and in particular to a new and useful method of forming an element having a symmetrically curved wall from buildup weld beads which are added during rotation of the element being formed.
The invention relates to a method of and apparatus for preparing from weld material, by the buildup thereof by multilayer buildup welding, a component having wall contours, more particularly diverging wall contours, with curvatures symmetrical in rotation. The treatment zone of the component is rotated around its axis of symmetry as rotational axis, being guided, while always remaining in a horizontal position for welding, along welding heads which remain stationary during the application of a discrete weld bead layer.
Making components entirely of weld material is known as form welding. The method can be used for the rapid and economic production of high grade products from low alloy and high alloy steels, such as connections or flanges or adapters for nuclear engineering purposes, the components having material qualities which comply with the most stringent material requirements. The kind of welding used is submerged welding, a mechanized method which is very productive and has proved very satisfactory in many areas of apparatus construction. The main advantages accruing from producing structural elements by form welding are relatively short production times, relatively low manufacturing costs and the possibility of an article being shaped integrally without a longitudinal seam.
In conventional submerged welding in which weld beads are applied in layers by means of melting electrodes, the treatment zone of an electrode must be guided along stationary welding heads while always remaining positioned horizontally for welding. This requirement causes considerable difficulties in the production of components which have wall contours, more particularly diverging wall contours, having rotationally symmetrical curvatures and which may be bulky and weigh several tons. The difficulties are heightened by the need for the welding heads to be guided very accurately in the horizontal position for welding if the end product is to be of the required high standards of material quality and free from any defect. Just a single discontinuity by a departure from correct guidance of the welding heads would lead to the end product being rejected in subsequent acceptance testing.